Lithium-ion battery, battery module, battery pack, and apparatus

A lithium-ion battery, comprising a positive electrode plate, a negative electrode plate, a separator, and a nonaqueous electrolyte, wherein

• the positive electrode plate comprises Li1+xNiaCobMe(1-a-b)O2-cYc, wherein −0.1≤x≤0.2, 0.8≤a<1, 0<b<1, 0<(1-a-b)<1, 0≤c<1, Me is selected from one or more of Mn, Al, Mg, Zn, Ga, Ba, Fe, Cr, Sn, V, Sc, Ti, and Zr, and Y is selected from one or more of F, Cl, and Br;
• the nonaqueous electrolyte comprises a nonaqueous solvent and a lithium salt, wherein the nonaqueous solvent comprises a carbonate solvent and a high oxidation potential solvent, and the high oxidation potential solvent is selected from one or more of compounds represented by formula I and formula II;
• in formula I, R1 and R2 are independently selected from unsubstituted, partially halogenated, or fully halogenated alkyl groups having 1 to 5 carbon atoms, and at least one of R1 and R2 is a partially halogenated or fully halogenated alkyl group having 1 to 5 carbon atoms;
• and
• in formula II, R3 is selected from partially halogenated or fully halogenated alkylidene groups having 1 to 6 carbon atoms, wherein
• a halogen atom is selected from one or more of F, Cl, Br, and I.